As wireless communication performed in aircrafts or ships, wireless communication using high-speed communication satellites is increasing in recent years.
In order to cope with an increase in demand for wireless communication using high-speed communication satellites, it is necessary to reduce the size of a coverage area of a beam radiated from an antenna to efficiently radiate a radio wave to a narrow area. Moreover, in order to cover a whole service area, it is necessary to provide a large number of spot beams.
For making it possible to radiate a radio wave to a narrow area effectively in a state where a large number of spot beams are provided, a multibeam antenna method is known.
In the multibeam antenna method, a plurality of beams is formed by a multibeam antenna device, and the multibeam antenna device includes, in addition to a plurality of radiating elements and reflecting mirrors, a multibeam forming circuit for outputting signals to the radiating elements.
The multibeam forming circuit further includes a two-way power divider for dividing power of an input signal into two, a three-way power divider for dividing power of an input signal into three, and a phase shifter.
The number of mounted two-way power dividers and the number of mounted three-way power dividers vary depending on the number of output signals of the multibeam forming circuit. For example, there is a case in which two two-way power dividers and two three-way power dividers are mounted in one-beam forming circuit.
The following Non-Patent Literature 1 discloses a three-way power divider including one input port for receiving a signal and three output ports for respectively outputting signals.
In this three-way power divider, installation position of the one input port and installation positions of the three output ports are on opposite sides.
Specifically, assuming that the origin on an X-Y plane is, for example, at a center position of the three-way power divider, an installation position of the one input port is (0, −Y) on the X-Y plane and installation positions of the three output ports are (−X, Y), (0, Y), (X, Y) on the X-Y plane.
In addition, two terminators are connected to the three-way power divider.